Download HighFour Biology Round 7 Category C: Grades 9 – 10 Monday, March

HighFour Biology Category C: Grades 9 – 10 Round 7 Monday, March 6, 2017 The use of calculator is not required. Answer #1: Solution: Answer #2: Solution: Answer #3: Solution: Answer #4: Solution: parallel evolution Two main types of evolution occur that result to species with similar morphological characteristics -­‐ convergent and parallel. Parallel evolution is the evolution of geographically separated groups in such a way that they show phenotypical similarities. symbiosis Symbiosis came from the Greek word meaning "living together". It refers to a close and often long-­‐term interaction between two different species. It can be classified as mutualistic, commensalistic, or parasitic, depending on the benefits and/or harm the organisms cause each other. It can also be obligatory and facultative. microspores A spore is a unit of asexual or sexual reproduction used by plant, algae, fungi, and protozoa. Microspores are structures that develop into a male gametophyte and form the sperm cells to fertilize the egg during the alternation of generations in many plants. Malpighian tubule The Malpighian tubule is a unique excretory organ of insects that empties into the digestive tract, removes nitrogenous wastes from the hemolymph, and functions in osmoregulation. The system was discovered in the 17th century, and was named after the scientist who discovered it, Marcello Malpighi. HighFour Biology Category C: Grades 9 – 10 Round 7 Monday, March 6, 2017 The use of calculator is not required. Answer #5: Solution: Answer #6: Solution: Answer #7: Solution: Answer #8: Solution: littoral zone A lake can be divided into two main zones: littoral and limnetic. The littoral zone is the shallow, well-­‐lit waters close to the shore. This allows for the growth of aquatic plants and provides a habitat for fish and other organisms that is very different from the open water environment. plastid Plastids are double-­‐membraned organelles that can only be found in plants and animals. Together with the mitochondria, it is responsible for energy production. It can also be used in storage of important chemical compounds used by the cell, such as fat and proteins. They may or may not contain pigment. Archaea The new three domain system that classifies life consists of eukaryotes, bacteria, and archaea. Archaea have been distinguished as a different set of organisms because albeit they are unicellular and resemble bacteria, they display characteristics found in multicellular organisms. They tend to favor extreme environments, such as extremely high temperatures and high salinity. Monera Kingdom Monera contains all prokaryotes. In the new three domain system of life, the organisms found in kingdom Monera have been divided into two domains, Archaea and Bacteria. HighFour Biology Category C: Grades 9 – 10 Round 7 Monday, March 6, 2017 The use of calculator is not required. Answer #9: Solution: Answer #10: Solution: Answer #11: Solution: Answer #12: Solution: histones Histones are involved in the first of three stages of DNA compaction. They are small proteins with a high proportion of positively charged amino acids that bind to the negatively charged DNA. A core of eight histone proteins at regular intervals form the nucleosome, which is the second stage of DNA compaction. accretion Accretion is the accumulation of marine sediments at the edges of a continent or continental plate. Other materials that may also build-­‐up include volcanic arcs, seamounts, or other igneous features. In some cases, accretion may form into entire coastal mountain ranges. invasive species Introduced species are species moved by humans, either intentionally or accidentally, from its native location to a new geographic region. However, when they propagate or reproduce too fast, they tend to spread to a degree that may damage the environment and harm other species. When this happens, they become invasive species. amensalism Amensalism is a relationship between two organisms of different species in which one organism is harmed or inhibited, while the other remains unaffected. An example of this is when a taller and wider plant deprives a smaller plant adjacent to it of sunlight. HighFour Biology Category C: Grades 9 – 10 Round 7 Monday, March 6, 2017 The use of calculator is not required. Answer #13: Solution: Answer #14: Solution: Answer #15: Solution: Answer #16: Solution: kinetoplast Kinetoplast DNA is unique to unicellular flagellated protozoans of the order Kinetoplastida. It is a giant network of circular DNA connected in a chain or series, resembling veil of armor. Majority of the organisms that have it are parasitic. To date, it is the most structurally complex mitochondrial DNA in nature. innate behavior Innate behavior is developmentally fixed and under strong genetic control. It is highly predictable and is shown by all individuals in a population throughout their lifetimes, regardless of the influences of internal and external environment. mutations Mutations are permanent changes of the nucleotide sequence of the DNA of an organism that may or may not alter its phenotype. They result from errors during DNA replication, or other external factors that result to damages in the DNA. When an organism with a mutation in its DNA reproduces, they pass on this mutation, effectively changing the genotype, and possibly the phenotype, of the next generation. pheromones Pheromones are species-­‐ or mating-­‐type-­‐specific hormonal chemicals secreted by an animal to communicate various messages to other animals to affect their behavior. They are probably the most ancient communication system in living organisms, being present in bacteria, protists and fungi. Although it is mainly used to attract mates of the opposite sex in insects, they can be used for communication, signaling danger, or marking of territory. HighFour Biology Category C: Grades 9 – 10 Round 7 Monday, March 6, 2017 The use of calculator is not required. Answer #17: Solution: Answer #18: Solution: Answer #19: Solution: Answer #20: Solution: intermediate filaments An intermediate filament is a component of the cytoskeleton that includes filaments intermediate in size between microtubules and microfilaments, usually around 10 nm. It is generally strong and ropelike, consisting of various types of proteins. They mainly provide strength and support for the fragile tubulin structures, being less dynamic than the other types of filaments. Chlamydomonas Chlamydomonas is the genus of unicellular flagellates that are likely to be the closest living organisms to the ancestor of green plants. Even though they are single-­‐celled, they have the capability for photosynthesis due to the presence of an eyespot, or channelrhodopsins, that detect and get activated by light. heterodonts Heterodonts are animals that have a variety of specialized teeth, such as incisors, canines, premolars, and molars. The presence of heterodont dentition suggests the degree of feeding/hunting specialization in a species. The smallest set of teeth in heterodonts belong to humans. saprobe A saprobe is an organism that derives its nutrition from the dead remains of other organisms, and decaying wood, leaves, litter, and other organic matter. Although some may be bacteria, most are fungi that can secrete enzymes to break down complex structures in plants, such as cellulose and lignin. Majority of fungi are too small to be seen with the naked eye, but others, such as mushrooms, can grow to a bigger size.